Infrared radiation from hot cones on cool conifers attracts seed-feeding insects.
Foraging animals use diverse cues to locate resources. Common foraging cues have visual, auditory, olfactory, tactile or gustatory characteristics. Here, we show a foraging herbivore using infrared (IR) radiation from living plants as a host-finding cue. We present data revealing that (i) conifer cones are warmer and emit more near-, mid- and long-range IR radiation than needles, (ii) cone-feeding western conifer seed bugs, Leptoglossus occidentalis (Hemiptera: Coreidae), possess IR receptive organs and orient towards experimental IR cues, and (iii) occlusion of the insects' IR receptors impairs IR perception. The conifers' cost of attracting cone-feeding insects may be offset by occasional mast seeding resulting in cone crops too large to be effectively exploited by herbivores.
Takács
Stephen
S
Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, Canada V5A 1S6.
Bottomley
Hannah
H
Andreller
Iisak
I
Zaradnik
Tracy
T
Schwarz
Joseph
J
Bennett
Robb
R
Strong
Ward
W
Gries
Gerhard
G
D000818:Animals; D003463:Cues; D005247:Feeding Behavior / Q000528:radiation effects; D005260:Female; D006358:Hot Temperature; D007259:Infrared Rays; D007313:Insecta / Q000502:physiology* / Q000528:radiation effects / Q000648:ultrastructure; D017956:Photoreceptor Cells, Invertebrate / Q000648:ultrastructure; D012639:Seeds; D064028:Tracheophyta